Friction block or shoe.



G. O. W. SIMPSON.

FRICTION BLOCK OR SHOE.

APPLIOATION FILED JANA, 1909.

931,093. Patented Aug. 17, 1909.

2 SHEETS-SHEET 1.

G. G. W. SIMPSON.

FRICTION BLOCK OR SHOE.

APPLIOAIION FILED JANA, 1909.

931,093. Patented A 17, 1909.

2 SEE SHEET 2.

W J1E 26 WK WMWM W GAZIL I minim a. mum! em Pwmumoaurkus mswucmn. u a

our... amiss PATENT onrron.

CHARLES CHRISTOPHER WOODMAN SIMPSON, OF WIGAN, ENGLAND.

FRICTION BLOCK OR SHOE.

To all whom it may concern:

Be it known that I, CHARLES CHRISTOPHER IVooDMAN SIMPSON, a subject of the King of Great Britain, residing at Vigan, in the county of Lancaster, in the Kingdom of England, have invented certain new and useful Improvements in or Relating to Friction Blocks or Shoes, of which the following is a specification.

This invention relates to cast iron brake blocks, electrical collector slippers, and like frictional shoes, and refers to that class of block provided with a shoe which when worn through can be detached, and a new one applied instead.

The invention will be understood from the following description, reference being had to the accompanying drawings, in which- Figure 1 is a perspective view showing the holder, shoe and locking pin separated; Fig. 2, the holder shoe and pin in position ready for use; Fig. 3, an elevation of a block and shoe of a different pattern separated; and Fig. 4, an elevation of the same ready for use.

As applied to brake blocks, I provide a shoe or wearing part A and a holder B. Its front face 6 is made the same curve as the rear face of the shoe A, and against this holder the shoe A can bed or seat itself, there being at or near each end of the shoe, a shoulder 0 which abuts against each end of the holder. In the holder is located the hanger holes E, and at rear of the holder is the ear D with transverse hole cl, through which a bolt L can be passed, and fastened by a split pin, cotter or nut, et cetera. The rear face of the shoe has a lug or knob F cast thereon, and the holder is made aw-shaped, or with a slot G or otherwise, to receive the lug F. Through the holder B and through the lug F, I drill a hole H, and by passing a pin I through these holes the shoe A is locked to the holder B, or by removing the pin I the shoe can be separated from the holder. This pin is made, at or near mid-length, with an oval or cam-shaped part 71, while for the remainder of its length it is round, and one end of the pin is provided with a radial arm J, with an embayment K at end, adapted to partly embrace the bolt L aforesaid. The locking pin hole at one side of the holder B is made of such a shape as to allow of the cam-shaped part 2' to be passed through it. Then when the pin is in position, by turning the said pin I a part of a turn, it will lock Specification of Letters Patent.

Application filed January 4, 1909.

Patented Aug. 17, 1909.

Serial No. 470,588.

itself in the holder and cannot be withdrawn. The hole H in the shoe lug F is enlarged, to permit of the cam shaped part 2' working therein.

The mode of action is as follows :To fasten the shoe to the holder, the shoe is presented rearwardly to the front face of the holder B, and the abutments C at the ends made to engage the holder. The locking pin I is then passed into the hole H, to lock the two parts together, and by turning it on its axis the cam-shaped part 2' is put eccentric with the hole II in the holder so that the pin cannot be withdrawn. In this position, the end of the arm J will lie in close proximity to the bolt hole (Z in the ear D of the holder.

The insertion of the bolt L therefore will engage the embayment K at the end of the arm J, and lock the arm, so that the pin I cannot be turned back. Consequently the shoe A cannot separate from the holder B, and the locking pin I cannot be withdrawn as it is held in the locked position by the bolt L engaging the arm J. Both the shoe and the holder are held locked together even if the shoe should break. A further feature is, that the turning of the arm J into the position shown in Fig. 2, will cause the cam 2' to bind against the slot H in the shoe and tighten it firmly against the holder B. To detach the shoe the cotter, split pin or nut is removed, the bolt L withdrawn, and the pin I turned into such a position, that its camshaped part 2' will register or come concentric with the hole H, so that it may be withdrawn. hen withdrawn, the shoe will then at once come off. The shoe by this invention can be worn down by use until quite thin before it is necessary to detach or replace it.

The block shown in Figs. 3 and 4 is constructed on exactly the same lines as already described, the main difference being that there are two lugs F on the rear of the shoe A, and two corresponding recesses G in the holder, and a pair of locking pins I with arms J. The arms are in this case not provided with an embayment at the ends, but have holes through which the pin L is passed. Furthermore the rear face of the shoe and the front face of the holder are in those figures made straight instead of curved. The same letters in these figures refer to like parts in Figs. 1 and 2.

I have described my invention more especially as applied to cast-iron brake blocks,

but it is obvious it can be applied equally well to electrical collector slippers, and like frictional shoes. The application of the invention to these purposes will be sufiiciently obvious without further description.

I declare that what I claim is 1. In a brake-block, a detachable portion or shoe in combination with a fastening for securing the same to the permanent portion, consisting of an interlocking pin having a cam-shaped part, which pin on being passed through transverse holes in the permanent portion and the removable shoe, and turned, locks by means of this cam-shaped part and the hole, the two portions, and binds them, together.

2. In a brake-block, the combination with a permanent portion or holder and a detachable portion or shoe, of a projecting portion or portions on one part, and a recessed portion or portions on the other part to receive the projecting portions, a pin having at or about mid-length a cam-shaped part passed through transverse holes in the said projecting portion and recessed portion, and so made that when turned into one position the pin will lock the shoe to the holder, or when turned into another position will enable the pin to be withdrawn and the shoe removed.

3. In a brake-block, the combination with a permanent portion or holder and a detachable portion or shoe, of a pin having at or about mid-length a cam shaped part passed through transverse holes in the lug and aw of the permanent and detachable portions of the block, the holes being so arranged that when the pin is turned in the hole its cam-shaped portion will bind against the sides of the hole in the lug and tighten the shoe against the holder.

4. In a brake-block, the combination with a permanent portion 01' holder and a detachable portion or shoe, of a pin having at or about mid-length a cam-shaped part passed through transverse holes in the said holder and shoe to interlock them together, a radial arm at the end of the pin and a bolt or pin passed through the permanent portion or holder for engaging the end of the said arm to hold it in the interlocking position.

In witness whereof, I have hereunto signed my name this 18 day of December, 1908, in the presence of two subscribing witnesses.

CHARLES CHRISTOPHER WOODMAN SIMPSON.

lVitnesses H. D. Jimrnsox, F. L. RAND. 

